The present invention relates to a method for manufacturing light emitting diode devices. Here, the light emitting diode (LED) device comprises an LED on a substrate, a transparent layer sealing the LED, and a reflection layer on the transparent layer.
FIGS. 6 and 7 are perspective views showing a conventional method for manufacturing LED devices.
Referring to FIG. 6, a plurality of LEDs 2 are securely mounted on a substrate aggregation 1. Each of the LEDs 2 is disposed at a central position of each division for a completed LED device. Each of the LEDs is connected to a circuit on a substrate of the division by bonding wires 3. A reflector aggregation 5 is prepared by the injection molding of a white resin such as liquid crystal polymer, PBT and PPS. The thickness of the reflector aggregation is larger than the height of the bonding wire 3. An opening 6 is formed in the division.
The substrate aggregation 1 and the reflector aggregation 5 are adhered to each other. A transparent resin such as epoxy resin is injected in each opening 6 to form a transparent layer 4. Because of the transparent resin, the transparent layer 4 can not be depicted in FIG. 7. However the reference numeral 4 is written in the figure for the convenience of explanation. Thus, the LED 2 is sealed by the transparent layer 4. After the solidifying of the transparent resin, the substrate aggregation 1 is cut by a dicing blade (not shown) along cutting lines 8, so that a complete LED comprising a substrate 1a, LED 2, a reflector frame 5a, and transparent layer 4 is produced.
In the above described method, it is difficult to coincide thermal expansion coefficients of the transparent resin for the transparent layer 4 and of the resin for the reflector aggregation 5 with each other, since a reflector agent is mixed in the reflector aggregation. As a result, there are troubles such as peel off of the LED, break off of the bonding wires, peel off of the reflector aggregation in heating processes.
Since the reflector aggregation is made by the injection molding, the reflector frame 5a can not be formed into a thin layer. Consequently, the LED device can not be made into a thin thickness.